Pressure-alarm for pneumatic tires.



G. A. GULVER.

PRESSURE ALARM FOR PNEUMATIG TIRES.

APPLICATION FILED Arms, 1913.

1,1 33,269. Patented Mar. 30, 1915.

25?.. M @YM um ED STATES PATENT oFFicE.

GEORGE A. CULVER, OF BEATRICE, NEBRASKA, ASSIGNOR OF ONE-HALF T0 THOMAS W'. KEENAN, OF' SHENANDOAH, IOWA.

PRESSURE-ALARM FOR PNEUMTIC TIRES.

Specification of Letters Patent. f

Patented Mar. 3o, 191e.,

Application tiled April 5, 1913. Serial No. 759,570.

To all whom. it may concern Be it known that l, GEORGE A. CULVER, citizen of the United States of America, and resident of Beatrice, Gage county, Nebraska, have invented a new and useful Pressure- Alarm for Pneumatic Tires, of which the following is a specification.

The object of this invention is to provide means adapted to be mounted on a pneumatic tire and designed to sound an audible alarm or signal when the pressure within said tire 4falls below a certain point.

A further object of this invention is to provide a device of the class described adapted to be mounted on the valve tube of a pneumatic tire and designed to overcome the valve spring when the pressure within said tire has been reduced below a predetermined and variable danger point, thereby permitting the escape of air through said tube to the end of sounding an audible alarm or signal.

A further object of this invention is to provide improved means for adjusting a pressure alarm for operation at variable degrecsof pressure within a tire.

My invention consists in the construction, arrangement and combination of elements hereinafter' set forth, pointed out in my claims and illustrae'dA by the accompanying drawings, in which-4n Figure 1 is an elevation illustrating my improved device mounted on a valve tube. Fig 2 is a longitudinal sectional elevation of the same. Fig. E is a longitudinal section-of the device on an enlarged scale;

It is a fact well lrnfwvn to users of automobiles and other vehicles equipped withpneumatic tires that a large proportion of the tire troubles and damage are occasionedv by running the vehicle on insufficiently inflated, or partially deflated, tires, the air 1n many 4cases having been lost through slow4 leaks the presence of which is unsuspected by the operator. This use of a partially defi-ated tire will often result yin cutting the tire to pieces and irreparably damaging it before its condition is suspected by the ope'rator, and l have provided means in this .said tire has fallen below a predetermined danger point, which is variable according to the conditions under which the tire is used.

In the construction and mounting ofthe device as shown the numeral 10 designates a. valve tube of any suitable construction, which tube preferably is exteriorall'y threaded. The tubey 10 is formed with an integral head 11 and removable washer 12 at its base adapted to engage opposite surfaces of an innertube of a pneumatic tire (not shown). A nut 13 is screwed on the tube 10 and is adapted to engage the outer face of a Wheel rim (not shown), and a binding nut 14 is also screwed on said tube and adapted to engage the nut 13, a leather washer, such as 15, ordinarily being interposed between said nuts. The binding nut is formed with an upwardly extending, exteriorly threaded neck portion 16 adapted to receive attachment of an interior-ly threaded closing cap or hood of common form (not shown) adapted to cover the entire tube 10 and valve members. The valve tube 10 is interiori? threaded at its tip and a binding nut El?, carrying a valve seat 18 at its lower end, is screwed therein. A valve stem 19 is mounted through the nut 17 and valve seat 18 and a valve 20 is fixed to said stern below said seat. The valve stem 19 extends into the tube 10 beyond the valve 2O and a head 21' is slidingly mounted thereon and engages an annular shoulder 22 within the bore of the tube 10 which limits downward movement thereof. The stem 19 is provided with means (notshown) engaging the head 21 and limiting outward movement of said stem relative to said hfead. An expansive spring 23 is coiled around the lower portion of the stem 19 and impinges' at its ends the head 21 and valve 2O respectively. 1t is the function of the spring 23 tovhold the valve 2O .normally against the seat 18 and'prevent engage and apply pressure at times on the' outer end portion of the valve stein'19. A collar 28 is formed on or fixed to the plunger 26 above the head 27 and said collar is adapted to lengage the outer end of the tip of the tube 10 and limit downward movement ofthe plunger 26 therein'. An expansive spring 29 is coiled around the plunger 26 and impinges at its ends the collar and adjusting nut 25 respectively. It is the function'of the. spring 29 to cause the plunger 26 to apply pressure on the valve stemI 19, and it is the function of the adjusting nut to regulate the tension of the spring 29 and determine the degree of such pressure. The casing 24 preferably is"re duced at its outer end and is threaded eX- teriorly, and a cap 30 is adapted to be screwed thereon, over the adjusting nut 25. The cap 30 carries at its outer end a signaling device oraudihle alarm such as a. whistle 31. I have here shown a whistle of the' double disk variety, which is simple and occuies small space, but it is to be'understood .hat any suitable form of whistle may be employed.

In practical use the signaling device, including the casing 24 and members carried thereby, Iis removed from the tube 10 during the process of inflation of the tire. The tire is then inflated to the degree, as shown by a tire pressure gage, which is believed to be the minimum pressure that can be used with safety, such for instance as forty pounds. The casing 24 is then mounted on the tube 10 in the position which it will occupy in use, and the cap 30 and whistle are removed to give access to the adjusting nut 25. The adjusting nut is then adjusted to the desired position in the outer end of the casing 24.-, to compress the spring 29 to the desired degree. It will be understood that the tension of the: valve spring 23 is dependent on the degree of pressure within the tire, owing to outward pressure on the head 21; and that by adjustment of the nut 425 the tension of the spring 29 may bemade to equal the tension of said spring 23. Consequently, after such equalization has been effected, a reduction of the pressure Within the tire will cause a reduction of the tension of the sprin 23 and ermits the plunger 26, under the mfluence o the sprlng 29, to more against the valve stem 19, open down to a position where it begins to open the valve, the casing 24 is removed from the tube 10 and the inflation continued to the desired extent. The casing 24 is then replaced on the tube 10 and the cap 30, with its whistle, ordinary closing cap or hood (not shown) may be screwed in place over all. Now it will readily be understood that when the pressure within the tire from any cause falls below the predetermined minimum of safety, such as forty pounds, the spring 29 will cause the valve to open as above described, and the air escaping from the tire through the tube 10, casing 24, adjusting nut 25 and cap 30 will cause the whistle 31 to sound and convey a signal to the operator that one of his tires requires attention. This will obviously prevent much damage to tires.

I' claim as my inventionj 1. The combination with a pneumatic tire inflation valve, of a low pressure signal device comprising a casing connected to the outer end of the valve tube, 'a hollow adjusting nut threaded into the outer end of said casing, a plunger mounted within said casing and nut centrally thereof and coaxial with the stem of said valve and having the inner end thereof in engagement with the adjacent end of the valve stem, a collar fixed to. said plunger, an expansion spring surrounding said stem between said collar and nut and adapted to be placed under tension by said nut whereby said plunger will move is screwed in place, and thek inwardly and open the valve against its,

spring when the pressure within the tire has fallen below a predetermined point, and a signal operated by air passing through the hollow nut and adapted to, sound upon the opening of said valve.

2. The combination with a, pneumatic tire inflation valve, of a low pressure signal device comprising a casing connected to the outer end of the valve tube, a hollow adj usting nut'threaded into the outer end of said casing, a plunger mounted within said casing and nut centrally thereof and coaxlal with'the stern of said valve and having the innerv end thereof in engagement with the adj cent end of the valve stem, a collar fixed to said plunger adjacent to the inner end thereof, an expansion spring surrounding said stem between said collar and nut and adapted to'be placedunder tension by said nut whereby said plunger will move 1nwardly and open the valve against its spring when the pressure within the tire has fallen below a predetermined point, and a signal connected to the outer end of said casing and vadaptedfto sound upon the opening of saidvalve.

3. The combination with a pneumatic tire inflation valve, of a low pressure signal device comprising a casing connected to the outer end of the valve tube, a hollow adjusting nut threaded into the outer end of said casing, a plungermounted within said casing and nut centrally thereof and coaxial with the stem of said valve and having the inner end thereof in engagementwith the adjacent end of the valve stem a collar fixed to said plunger adjacent to the inner end thereof, an expansion spring surrounding said stem between said collar and nut and adapted to be placed under tension b v said nut whereby said plunger will move inwardly and open the valve against its spring when the pressure within the tire has fallen below a predetermined point, a cap threaded onto the outer end of sa-id casing concentrically of said plunger, and a signal carried by said cap and coaxial therewith.

4. The combination with a pneumatic tire inflation valve, of a low pressure signal device comprising a casing connected to the outer end of the valve tube and having the outer end thereof circumferentially reduced, a hollow adjusting nut threaded into the outer end of said casing, a plunger mounted within said casing and nut centrally thereof .and coaxial with the stem of said valve, a head on the inner end of said Stem and in engagement with said valve Stem, a collar fixed to said plunger adjacent to saidfhead, an expansion spring surrounding said stem between said collar and nut and adapted to be placed under tension by said nut whereby said plunger will move inwardly and open the valve against its spring when the pressure within the tire has fallen below a predetermined point, a cap threaded onto the reduced end of said casing concentrically of said plunger, and a signal carried by said cap and coaxial therewith.

Signed by me at Des Moines, Iowa, this twenty-ninth day of March, 1913.

GEORGE A, CUL VER.

Witnesses:

W. W. FINK, EARL M. SINCLAIR. 

